This invention relates to cooling the vane of a gas turbine engine and particularly to cooling the trailing edge of the platform of the vane that is mounted ahead of and adjacent to the high pressure turbine.
As one skilled in the aeronautical gas turbine engine technology recognizes, the air discharging from the compressor section is typically utilized for cooling engine components located downstream of the compressor. It is abundantly important in designing gas turbine engines that the compressor air be used conservatively so that the quantity of air used for cooling matches the cooling demand of the component being cooled. In other words, any excessive air utilized for cooling results in a deficit to engine performance.
The problem that this invention solved is where air taken from the compressor, particularly the air that is taken off the root of the compressor blades is utilized in cooling certain parts and since this air is hotter than other portions of the air taken off lower stations in the compressor, it is typically dumped into the engine""s gas stream that constitutes the working medium of the engine. The air could be used for turbine blade cooling, however, the additional temperature rise associated with the pump work makes this a very unattractive option because no performance benefit would be achieved. Hence, the compressor hub leakage air together with the cooling air is dumped through the sealing system into the cavity that is located at the front of the high pressure turbine. It is obvious, that under these circumstances, this air is not utilized to its maximum potential for cooling purposes since it is dumped prior to when it could be utilized for cooling other components of the engine. Heretofore, cooling of the leading and trailing edges of the inner diameter platform of the vane was by utilizing additional cooling air that discharges from the compressor and routed to the inner diameter liner of the combustor.
This invention contemplates utilizing the compressor discharge air that was heretofore dumped in the engine""s fluid working medium to cool the trailing edge of the inner platform of the high pressure turbine vane by judiciously and discretely routing the hub leakage and compressor cooling air through the support structure to bypass the path that is utilized to dump this air into the engine""s fluid working medium.
An object of this invention is to provide an improved cooling of the vane of a gas turbine engine by utilizing the heretofore compressor hub leakage and cooling air that was dumped into the engine""s fluid working medium.
A feature of this invention is to judiciously route the compressor leakage and cooling air so as to cool the trailing edge of the platform of the high pressure turbine vane of a gas turbine engine.